When Tobacco and Cannabis Use Motives Interact: Implications for Dependence and Quitting

Background Tobacco and cannabis co-use is a major public health issue among young adults. Little is known about how motives for using these substances interact and affect co-use behaviors. This study explores these associations and identify distinct motivational profiles among young people who co-use.Methods A cross-sectional survey was conducted among 357 French young adults (18–30 years; 54.9% men) reporting co-use. Participants indicated (Yes/No) their endorsement of 21 motives (10 tobacco-related, 11 cannabis-related, 7 shared). Correlations were computed between all motives. Hierarchical clustering identified distinct motivational profiles. Associations between profiles, motives, dependence, and readiness to quit were examined using regression models.Results Most within-substance motives and all shared cross-substance motives were correlated. Three clusters emerged: (1) high tobacco/moderate cannabis motive endorsement (n = 188), with high nicotine dependence; (2) low overall motive endorsement (except pleasure) and low dependence levels (n = 39); and (3) high endorsement of both tobacco and cannabis motives, with high dependence levels (n = 130). The number of endorsed tobacco motives was negatively associated with readiness to quit tobacco but positively associated with readiness to quit cannabis.Conclusions While tobacco and cannabis motives overlapped, these findings underscore the need to consider motivational patterns when designing tailored interventions to reduce co-use-related harms.